Epoxy is used in many applications including the encapsulation of such items as semiconductors and electronic circuitry modules. Epoxy is formed by mixing a resin with a catalyst in appropriate ratios and then baking the resin and catalyst mixture. Various devices are used to combine the resin and catalyst in the appropriate ratio and dispense the resin and catalyst mixture in an appropriate manner depending on the desired application. Such devices, however, require that the supply of mixed and degassed resin be available prior to dispensing.
While the catalyst is a free flowing liquid having a low viscosity on the order of seven hundred and fifty centipoise (cPs), resin is a highly viscous liquid with a viscosity on the order of seven thousand five hundred cPs. The low viscosity of the catalyst allows air bubbles, which may be present in the catalyst, to easily exit the catalyst. On the other hand, the highly viscous nature of the resin, due in part to the large amount of filler which constitutes the resin, results in air bubbles becoming trapped within the resin. Therefore, in addition to mixing the resin to uniformly distribute the filler, the resin is degassed prior to its combination with the catalyst. Currently, when devices which combine and dispense the resin and catalyst run out of; or otherwise require the addition of resin, the devices are shut down while additional resin is added, mixed and degassed. The current devices are, therefore, inefficient in that during the down-time required to resupply the devices with resin, the devices are unable to dispense the resin and catalyst mixture.
It would be advantageous, therefore, to devise a method and apparatus for generating a continuous source of mixed and degassed resin for use in devices which combine and dispense a resin and catalyst mixture.